In 1932 the groundbreaking physicist Wolfgang Pauli met the pioneering psychoanalyst Carl Jung. Pauli was fascinated by the inner reaches of his own psyche and not afraid to dabble in the occult, while Jung looked to science for answers to the psychological questions that tormented him; both were obsessed with discovering the full significance of the number 137, which describes the fine-structure constant of the atom and also happens to be the sum of the Hebrew letters of the word "Kabbalah." This double biography traces their extraordinary and fruitful collaboration, a journey that looked to the ancient secrets of alchemy, the work of Johannes Kepler, and the I Ching.

"The heart of this book lies not in the promised decipherment of the title but in Miller's excellent dual biography of two men who changed their fields.... A series of Pauli's vivid dreams, together with Jung's analysis of them, forms an unexpectedly rich centerpiece of the book."—Booklist

"Arthur I. Miller is a master at capturing the intersection of creativity and intelligence. He did it with Einstein and Picasso, and now he does it with Pauli and Jung. Their shared obsession with the number 137 provides a window into their genius."—Walter Isaacson